Pressure valve control method for automatic transmissions

Abstract

This invention provides a pressure valve control method for an automatic transmission, comprising: collecting vehicle operating parameters and determining whether the break-in activation conditions are met based on the vehicle operating parameters; if met, activating the break-in step; the break-in step comprising: controlling the pressure valve current to switch between a minimum value and a target value, wherein switching to the target value a predetermined number of times; collecting clutch status information and obtaining pressure valve break-in information based on the clutch status information; determining whether the pressure valve break-in is complete based on the pressure valve break-in information; and exiting the break-in step if the pressure valve break-in is complete. This pressure valve control method of the present invention, when the vehicle is parked and the oil temperature is low, performs pressure valve break-in when there is a risk of clutch pressure valve jamming, thereby reducing the probability of pressure valve jamming.

Description

Technical Field

[0001] This invention relates to the field of automotive transmission control technology, and in particular to a pressure valve control method for automatic transmissions. Background Technology

[0002] Dual-clutch transmissions (DCTs) have advantages such as seamless gear shifting, high transmission efficiency, and low fuel consumption. They are currently the most widely used automatic transmissions in automobiles, suitable for traditional internal combustion engine vehicles, and also used in hybrid vehicles of various structural forms.

[0003] In dual-clutch transmissions, a pressure valve typically drives the clutch actuator to complete gear shifting. This pressure valve is usually a solenoid valve, and the working medium is hydraulic oil. See [link to specific structure] for details. Figure 1 Under the action of the return spring 1, the valve core 2 of the solenoid valve is initially in the left position and in the initial closed state. When the solenoid valve is energized, the electromagnetic force of the electromagnet 3 overcomes the force of the return spring 1 and other load forces, pushing the valve core 2 of the solenoid valve to move to the right. After that, the P port and A port of the solenoid valve are connected, and the hydraulic oil flows through the main inlet port P and enters the output port A through the solenoid valve. However, when the ambient temperature is low and the vehicle has been stationary for a long time, the viscosity of the hydraulic oil is high, and the initial load force of the solenoid valve is large. In addition, if the valve core 2 of the solenoid valve is eccentric, for example... Figure 1 The viscous friction at positions 4 and 5 of the solenoid valve further increases the resistance to valve core movement. When the step size of the change in the solenoid valve's energizing current (the step current from when the solenoid valve is closed to when it is open) is small, although according to the solenoid valve's pressure-current characteristic, the energizing current corresponds to the solenoid valve's opening position, it may occur at a certain position before the valve port opens, reaching the valve core's equilibrium position, causing the solenoid valve to jam. This prevents hydraulic oil from entering the clutch chamber through port A, and the clutch chamber cannot build up pressure to the expected pressure. Summary of the Invention

[0004] The purpose of this invention is to solve the problem of clutch pressure valve jamming risk in existing automatic transmission pressure valve control methods when the vehicle is stationary for a long time in low temperature environments.

[0005] To solve the above-mentioned technical problems, the present invention provides a pressure valve control method for an automatic transmission, comprising:

[0006] Collect vehicle operating parameters and determine whether the break-in activation conditions are met based on the vehicle operating parameters. The break-in activation conditions include: the transmission controller is powered on, the actual gear of the transmission is in neutral, the parking position is in parking, the engine is not started, and the hydraulic oil temperature of the pressure valve is lower than the temperature threshold.

[0007] If the conditions are met, the break-in process is initiated; if not, the process continues to assess the condition.

[0008] The break-in process includes the following steps:

[0009] Control the pressure valve current to switch between the minimum and target values ​​a predetermined number of times;

[0010] Collect clutch status information and obtain pressure valve break-in information based on the clutch status information;

[0011] Determine whether the pressure valve break-in is complete based on the break-in information; if the break-in is complete, exit the break-in process.

[0012] Clutch status information includes clutch pressure, and pressure valve break-in information includes the number of break-in responses. The method for obtaining the number of break-in responses includes determining that each time the control pressure valve current reaches a target value and the clutch pressure reaches a response pressure threshold, the break-in response is considered complete.

[0013] The steps to determine whether the pressure valve break-in is complete include determining whether the number of consecutive break-in responses has reached a threshold; when the number of consecutive break-in responses reaches the threshold, the pressure valve break-in is considered complete, and the break-in process is terminated.

[0014] Using the above method, when the vehicle is parked and the oil temperature is low, there is a risk of the clutch pressure valve sticking. The break-in status of the pressure valve is judged based on at least the number of break-in response times. The break-in status of the pressure valve is used as a condition for controlling the pressure valve to exit the break-in process, which can reduce the probability of pressure valve sticking.

[0015] According to another specific embodiment of the present invention, the pressure valve control method disclosed in the embodiment of the present invention uses a step method to control the pressure valve current to switch between a minimum value and a target value; and controls the pressure valve current to remain at the target value for a time t1 and at the minimum value for a time t2.

[0016] By adopting the above scheme, the pressure valve current is controlled to switch quickly between the minimum and target values, saving current switching time and accelerating the break-in operation. The pressure valve current is controlled to remain at the minimum and maximum values ​​for a certain period of time, giving the clutch pressure change time to reach a certain pressure, which is convenient for judgment.

[0017] According to another specific embodiment of the present invention, the pressure valve control method disclosed in the embodiment of the present invention has a minimum pressure valve current of 0mA and a target value of 1500mA; t1 and t2 are both 100ms.

[0018] According to another specific embodiment of the present invention, the pressure valve control method disclosed in the embodiment of the present invention further includes the pressure valve break-in information including the number of break-in executions, which is equal to a predetermined number; the step of determining whether the pressure valve break-in is completed further includes determining whether the number of break-in executions has reached a threshold number of executions; when the number of consecutive break-in responses does not reach the response threshold number, and when the number of break-in executions reaches the execution threshold number, the pressure valve break-in is determined to be complete; when the number of consecutive break-in responses does not reach the response threshold number, and when the number of break-in executions does not reach the execution threshold number, the pressure valve break-in is determined to be incomplete, and the break-in process continues.

[0019] By adopting the above scheme, when the number of responses in the break-in step does not reach the response threshold, the break-in process is performed as much as possible within the executable time to minimize the risk of stalling.

[0020] According to another specific embodiment of the present invention, the pressure valve control method disclosed in the present invention includes the following method for obtaining the number of break-in executions: when the break-in response is completed once, the control pressure valve current is switched to the minimum value, and the number of break-in executions is calculated to be completed once; when the control pressure valve current reaches the target value each time, but the clutch pressure does not reach the response pressure threshold, it is determined whether the duration of the control pressure valve current at the target value reaches t1; if the duration does not reach t1, it is further determined whether the clutch pressure reaches the response pressure threshold; if the duration reaches t1, the control pressure valve current is switched to the minimum value, and the number of break-in executions is completed once.

[0021] By adopting the above method, it can be ensured that each break-in period is completed within the predetermined time.

[0022] According to another specific embodiment of the present invention, the pressure valve control method disclosed in the embodiment of the present invention has an execution threshold of 6-10 times.

[0023] By adopting the above method, it can be ensured that each break-in period is completed within the predetermined time.

[0024] According to another specific embodiment of the present invention, the pressure valve control method disclosed in this embodiment includes a break-in step comprising:

[0025] S1: Control the pressure valve current of the odd clutch to switch between the minimum value and the target value a predetermined number of times; collect the status information of the odd clutch, and obtain the pressure valve break-in information of the odd clutch based on the status information; determine whether the pressure valve break-in of the odd clutch is completed based on the pressure valve break-in information; when the pressure valve break-in of the odd clutch is completed, proceed to step S2.

[0026] S2: Control the pressure valve current of the even-numbered clutch to switch between the minimum and target values ​​a predetermined number of times; collect the status information of the even-numbered clutch and obtain the pressure valve break-in information of the even-numbered clutch based on the status information; determine whether the pressure valve break-in of the even-numbered clutch is complete based on the pressure valve break-in information; when the pressure valve break-in of the even-numbered clutch is complete, exit the break-in step.

[0027] According to another specific embodiment of the present invention, the pressure valve control method disclosed in the embodiment of the present invention further includes the following break-in activation conditions: the engine downtime is greater than the downtime threshold.

[0028] According to another specific embodiment of the present invention, the pressure valve control method disclosed in the embodiment of the present invention has a temperature threshold of 0-4℃ and a shutdown time threshold of 30-40min.

[0029] According to another specific embodiment of the present invention, the pressure valve control method disclosed in the embodiment of the present invention has a predetermined number of times of 3-10 times and a response number threshold of 2-7 times.

[0030] The beneficial effects of this invention are:

[0031] The pressure valve control method provided by this invention activates the pressure valve for break-in when the vehicle is parked and the oil temperature is low, posing a risk of clutch pressure valve jamming. It also determines the completion status of the pressure valve break-in based on at least the number of break-in response counts, using the completion status of the pressure valve break-in as a condition for controlling the pressure valve to exit the break-in process, thereby reducing the probability of pressure valve jamming. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the pressure valve in a dual-clutch transmission.

[0033] Figure 2 This is a schematic flowchart of the pressure valve control method of the present invention;

[0034] Figure 3 This is a comparison chart showing the relationship between some vehicle operating parameters, break-in period, and pressure request changes in the pressure valve control method of the present invention.

[0035] Figure 4 This is a schematic diagram of the pressure valve current switching waveform during the break-in process of the pressure valve control method of the present invention.

[0036] Figure 5 This is a schematic flowchart illustrating the break-in process of a specific embodiment of the pressure valve control method of the present invention.

[0037] Explanation of reference numerals in the attached figures:

[0038] 1: Return spring; 2: Valve core; 3: Electromagnet; 4: First position; 5: Second position; P: Main oil inlet; A: Output port. Detailed Implementation

[0039] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. Although the description of the present invention is presented in conjunction with preferred embodiments, this does not mean that the features of the invention are limited to these embodiments. On the contrary, the purpose of describing the invention in conjunction with embodiments is to cover other options or modifications that may be derived based on the claims of the present invention. To provide a deep understanding of the invention, many specific details will be included in the following description. The invention may also be implemented without using these details. Furthermore, to avoid confusion or obscuring the focus of the invention, some specific details will be omitted in the description. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0040] It should be noted that in this specification, similar reference numerals and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0041] In the description of this embodiment, it should be noted that the terms "upper", "lower", "inner", "bottom", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship that the product of the invention is usually placed in during use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the present invention.

[0042] The terms “first”, “second”, etc., are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0043] In the description of this embodiment, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set up," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this embodiment based on the specific circumstances.

[0044] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0045] The present invention provides a pressure valve control method for an automatic transmission, wherein the method is performed by a control unit in the vehicle, specifically a transmission controller (TCU).

[0046] The pressure valve control method includes: collecting vehicle operating parameters and determining whether the break-in activation conditions are met based on the vehicle operating parameters, such as... Figure 2 and Figure 3 As shown, the break-in activation conditions include: the transmission controller is powered on, the actual gear position of the transmission is neutral, the parking position is park, the engine is not started (engine speed is 0), and the hydraulic oil temperature of the pressure valve is lower than the temperature threshold. The order of data collection and judgment can be as follows: Figure 2 The following steps are performed sequentially. If the conditions are met, there is a risk of the clutch pressure valve sticking, and the break-in process is initiated; if not, the process continues.

[0047] Specifically, the control unit (TCU) collects vehicle operating parameters through parking sensors, gear position sensors, temperature sensors, etc. The specific value of the temperature threshold is determined based on the viscosity characteristics of the clutch hydraulic oil, and a low temperature range with relatively high viscosity is selected, for example, a value between -4 and 4℃.

[0048] It should be noted that the break-in activation conditions in this invention ensure that the break-in process is performed a period of time after the vehicle is powered on but before the engine starts, and that there is a risk of jamming. Therefore, the break-in activation conditions may also include other conditions that may increase the risk of jamming, such as the duration of parking. After activating the break-in process, as follows... Figures 2-4 As shown, the break-in process includes:

[0049] Control the pressure valve current to switch between the minimum value I2 and the target value I1 a predetermined number of times; collect the clutch status information and obtain the pressure valve break-in information based on the clutch status information; determine whether the pressure valve break-in is complete based on the pressure valve break-in information; if the pressure valve break-in is complete, exit the break-in step.

[0050] The clutch status information includes clutch pressure, and the pressure valve break-in information includes the number of break-in responses. Methods for obtaining the number of break-in responses include, for example... Figure 2 As shown, the break-in response is completed once each time the current of the control pressure valve reaches the target value and the clutch pressure reaches the response pressure threshold.

[0051] Furthermore, the steps for determining whether the pressure valve has completed its break-in process include determining whether the number of consecutive break-in responses has reached a threshold; when the number of consecutive break-in responses reaches the threshold, the pressure valve is determined to have completed its break-in process, and the break-in process is terminated.

[0052] Specifically, the pressure valve current is controlled at its minimum value to request the minimum clutch pressure, and then switched to the target value to request the corresponding clutch pressure. The minimum value can be 0mA, and the target value can be a specific value or maximum value within the control range of the pressure valve, such as 800mA, 1000mA, 1200mA, 1500mA, etc. The predetermined number of pressure valve current switching operations is determined based on the target value, the dwell time at the maximum and minimum values, the switching speed, the duration of the break-in process, and the break-in effect, through experiments or experience. The break-in process can be completed before engine startup. Specifically, the number of times the current is switched to the target value can be 2, 3, 4, etc.

[0053] The control unit (TCU) also collects clutch pressure via a pressure sensor. The response pressure value is determined based on the clutch pressure requested by the target value. Specifically, it is the clutch pressure that can be reached under normal conditions and within a certain time when the pressure valve reaches the target value. This can be the clutch pressure requested by the target value, or it can be less than the clutch pressure requested by the target value. The response number threshold is determined based on the predetermined number of times the pressure valve current switches between the minimum and target values, the break-in effect, and experience. For example, if the number of switches to the target value is 3, the response number threshold can be 2 consecutive times. Furthermore, if the break-in response is completed in the first two switches, the predetermined number of switches can be changed to 2 times to complete the break-in process, saving time. The break-in process is exited if it is determined to be complete; if it is determined to be incomplete, the break-in is repeated until the completion conditions are met; or the break-in process is exited if the vehicle operating parameters determine that the break-in activation conditions are not met. Figure 3 This is a comparison chart showing the relationship between the actual gear position of the transmission, parking position, engine speed, hydraulic oil temperature and the break-in period, as well as the pressure request of the pressure valve in the vehicle's operating parameters. The break-in period is activated when the vehicle's operating parameters meet the activation conditions, and the break-in process is terminated when the engine is started or the hydraulic oil temperature exceeds the temperature threshold.

[0054] By employing the above-described solution, the pressure valve control method provided by this invention activates the pressure valve break-in process when the vehicle is parked and the oil temperature is low, posing a risk of clutch pressure valve sticking. Furthermore, it determines the completion of the pressure valve break-in process based on at least the number of break-in response cycles, using this completion status as a condition for controlling the pressure valve to exit the break-in phase, thereby reducing the probability of pressure valve sticking. This method can be applied to both traditional internal combustion engine vehicles and hybrid vehicles equipped with dual-clutch transmissions.

[0055] According to another specific embodiment of the present invention, such as Figure 4 As shown, the step method is used to control the pressure valve current to switch between the minimum value I2 and the target value I1; and the pressure valve current is controlled to remain at the target value for a time t1 and at the minimum value for a time t2.

[0056] The above scheme controls the pressure valve current to switch rapidly between the minimum and target values, saving current switching time and accelerating the break-in process. It also controls the pressure valve current to remain at the minimum and target values ​​for a certain period, providing time for the clutch pressure to change and reach a specific pressure, facilitating judgment. t1 and t2 can be determined based on the time required for the clutch to reach the requested pressure value when the pressure valve current is controlled to the target and minimum values, respectively. t1 and t2 can be equal to or less than the required time, and the response pressure threshold can be determined based on t1.

[0057] According to another specific embodiment of the present invention, the minimum value of the pressure valve current is 0mA, and the target value is 1500mA, which is the maximum value in the control range of the pressure valve; t1 and t2 are both 100ms, so as to give the clutch pressure the time to reach the response pressure value.

[0058] Based on the above values, the response pressure threshold is illustrated below with an example. When the pressure valve current is switched to the target value of 1500mA, the requested clutch pressure is approximately 48 bar. According to the test, at 20°C, it takes 150ms for the clutch pressure to reach the target pressure of 48 bar. Both t1 and t2 are set to 100ms. The pressure that the clutch can reach within this time is set as the response pressure threshold, for example, it can be set to 28~38 bar.

[0059] According to another specific embodiment of the present invention, such as Figure 2 As shown, the pressure valve break-in information also includes the number of break-in executions, which is equal to the predetermined number of times, i.e., the number of times the pressure valve current switches to the target value; the step of determining whether the pressure valve break-in is complete also includes determining whether the number of break-in executions has reached the execution number threshold.

[0060] If the number of consecutive break-in responses does not reach the response threshold, but the number of break-in executions reaches the execution threshold, the pressure valve is considered to have completed break-in. If the number of consecutive break-in responses does not reach the response threshold, and the number of break-in executions does not reach the execution threshold, the pressure valve is considered to have not completed break-in, and the break-in process continues.

[0061] The execution threshold can be determined based on the duration of the break-in process. To minimize the impact on normal functionality, the break-in process should be shortened as much as possible. Furthermore, if the number of responses during the break-in process does not reach the response threshold, there may still be a risk of stalling. In this case, the break-in process should be performed as many times as possible within the executable time to reduce the risk of stalling.

[0062] According to another specific embodiment of the present invention, such as Figure 2As shown, the method for obtaining the number of break-in executions includes: when obtaining the number of break-in responses, when the control pressure valve current reaches the target value and the clutch pressure reaches the response pressure threshold, that is, when the break-in response is completed once, the control pressure valve current switches to the minimum value, the break-in execution count is completed once, and the break-in execution count is incremented by 1. When the control pressure valve current reaches the target value but the clutch pressure does not reach the response pressure threshold, it is determined whether the duration of the control pressure valve current at the target value reaches t1; if the duration does not reach t1, it is further determined whether the clutch pressure reaches the response pressure threshold; if the duration reaches t1, the control pressure valve current switches to the minimum value, the break-in execution count is completed once, and the break-in execution count is incremented by 1.

[0063] Specifically, this implementation method is a logical approach to obtain the number of break-in responses. When the current of the control pressure valve reaches the target value, the clutch pressure is obtained. The clutch pressure may rise quickly to reach the response pressure threshold, in which case the number of break-in responses is incremented by 1. Alternatively, the clutch pressure may rise relatively slowly and fail to reach the response pressure threshold within a certain time. In this case, it is necessary to determine whether the duration of the pressure valve current at the target value reaches t1. If t1 is reached, it indicates that the break-in response is unsuccessful and the break-in effect is poor. It is not necessary to continue to judge the clutch pressure. The current value is switched as soon as possible to ensure that each break-in is completed within the predetermined time.

[0064] According to another specific embodiment of the present invention, the execution number threshold is 6-10 times. Specifically, when a step-type switching is adopted, and t1 and t2 are 100ms, the time between each switch to the target value and the next target value is 200ms, so the time for 6-10 times is 1.2 to 2s.

[0065] According to another specific embodiment of the present invention, such as Figure 5 As shown, the break-in process includes:

[0066] S1: Control the pressure valve current of the odd clutch to switch between the minimum value and the target value a predetermined number of times; collect the status information of the odd clutch, and obtain the pressure valve break-in information of the odd clutch based on the status information; determine whether the pressure valve break-in of the odd clutch is completed based on the pressure valve break-in information; when the pressure valve break-in of the odd clutch is completed, proceed to step S2.

[0067] S2: Control the pressure valve current of the even-numbered clutch to switch between the minimum and target values ​​a predetermined number of times; collect the status information of the even-numbered clutch and obtain the pressure valve break-in information of the even-numbered clutch based on the status information; determine whether the pressure valve break-in of the even-numbered clutch is complete based on the pressure valve break-in information; when the pressure valve break-in of the even-numbered clutch is complete, exit the break-in step.

[0068] It should be noted that the break-in process of this invention can be performed on both odd-numbered and even-numbered clutches simultaneously, or it can be performed on one type of clutch first, followed by the other. In this embodiment, the odd-numbered clutches are activated for break-in first, and the even-numbered clutches are activated after the odd-numbered clutches have completed their break-in process. This is because after starting the vehicle, the forward gear is generally used first, and as... Figure 3 As shown, when shifting into first gear, the break-in process has limited time. Therefore, the odd-numbered clutch break-in control is activated first to ensure the odd-numbered clutches complete their break-in process as early as possible, reducing the risk of jamming and preventing problems during vehicle startup. Furthermore, the sum of the odd-numbered and even-numbered break-in cycles represents the total break-in cycle count of this invention.

[0069] According to another specific embodiment of the present invention, the break-in activation condition further includes: the engine downtime is greater than a downtime threshold. This embodiment uses downtime as the break-in activation condition based on the fact that the probability of pressure valve sticking increases with increasing engine downtime.

[0070] According to another specific embodiment of the present invention, the temperature threshold is 0-4℃, more specifically 0℃; the downtime threshold is 30-40min, more specifically 30min.

[0071] According to another specific embodiment of the present invention, the predetermined number of times is 3-10 times, and the threshold number of responses is 2-7 times; wherein, the predetermined number of times can be adjusted according to the response situation, i.e., the break-in effect. If the break-in effect is good, the predetermined number of times is reduced; in addition, when odd-numbered clutches and even-numbered clutches are broken in separately, the predetermined number of times is also higher; the number of responses is determined according to the predetermined number of times.

[0072] While the present invention has been illustrated and described with reference to certain preferred embodiments, those skilled in the art should understand that the above description is a further detailed explanation of the invention in conjunction with specific embodiments, and should not be construed as limiting the specific implementation of the invention to these descriptions. Various changes in form and detail can be made by those skilled in the art, including several simple deductions or substitutions, without departing from the spirit and scope of the invention.

Claims

1. A pressure valve control method for an automatic transmission, characterized in that, The pressure valve control method includes: Collect vehicle operating parameters and determine whether the break-in activation conditions are met based on the vehicle operating parameters. The break-in activation conditions include: the transmission controller is powered on, the actual gear of the transmission is in neutral, the parking position is in parking, the engine is not started, and the hydraulic oil temperature of the pressure valve is lower than the temperature threshold. If the conditions are met, the break-in process will be activated. If the condition is not met, continue the evaluation. The break-in process includes the following steps: The pressure valve current is switched between a minimum value and a target value, wherein the switch to the target value is performed a predetermined number of times. Collect clutch status information and obtain pressure valve break-in information based on the clutch status information; The break-in information of the pressure valve is used to determine whether the break-in process is complete; if the break-in process is complete, the break-in step is terminated; wherein, The clutch status information includes clutch pressure, and the pressure valve break-in information includes the number of break-in responses. The method for obtaining the number of break-in responses includes determining that each time the pressure valve current reaches the target value and the clutch pressure reaches a response pressure threshold, the break-in response is completed once. The step of determining whether the pressure valve has completed its break-in process includes determining whether the number of consecutive break-in responses has reached a response count threshold. When the number of consecutive break-in responses reaches the response count threshold, the pressure valve is determined to be broken in, and the break-in process is terminated.

2. The pressure valve control method as described in claim 1, characterized in that, The pressure valve current is controlled to switch between the minimum value and the target value using a step method; and the pressure valve current is controlled to remain at the target value for a time t1 and at the minimum value for a time t2.

3. The pressure valve control method as described in claim 2, characterized in that, The minimum value of the pressure valve current is 0mA, and the target value is 1500mA; both t1 and t2 are 100ms.

4. The pressure valve control method as described in claim 2, characterized in that, The pressure valve break-in information also includes the number of break-in operations, which is equal to the predetermined number of operations. The step of determining whether the pressure valve has completed its break-in process also includes determining whether the number of break-in operations has reached a threshold. If the number of consecutive break-in responses does not reach the response count threshold, and the number of break-in executions reaches the execution count threshold, the pressure valve is determined to be broken in. If the number of consecutive break-in responses does not reach the response count threshold, and the number of break-in executions does not reach the execution count threshold, it is determined that the pressure valve break-in is not complete, and the break-in process continues.

5. The pressure valve control method as described in claim 4, characterized in that, The method for obtaining the number of break-in executions includes: when the break-in response is completed once, controlling the pressure valve current to switch to the minimum value, and the number of break-in executions is completed once; When the pressure valve current reaches the target value each time, but the clutch pressure does not reach the response pressure threshold, it is determined whether the duration of controlling the pressure valve current at the target value reaches t1. If the duration does not reach t1, then continue to determine whether the clutch pressure has reached the response pressure threshold. If the duration reaches t1, the pressure valve current is switched to the minimum value, and the break-in process is completed once.

6. The pressure valve control method as described in claim 5, characterized in that, The threshold for the number of executions is 6-10 times.

7. The pressure valve control method as described in claim 1, characterized in that, The break-in process includes: S1: Control the pressure valve current of the odd-numbered clutch to switch between the minimum value and the target value a predetermined number of times; collect the status information of the odd-numbered clutch, and obtain the pressure valve break-in information of the odd-numbered clutch based on the status information; determine whether the pressure valve break-in of the odd-numbered clutch is completed based on the pressure valve break-in information; when the pressure valve break-in of the odd-numbered clutch is completed, proceed to step S2. S2: Control the pressure valve current of the even-numbered clutch to switch between the minimum value and the target value a predetermined number of times; collect the status information of the even-numbered clutch, and obtain the pressure valve break-in information of the even-numbered clutch based on the status information; determine whether the pressure valve break-in of the even-numbered clutch is completed based on the pressure valve break-in information; when the pressure valve break-in of the even-numbered clutch is completed, exit the break-in step.

8. The pressure valve control method according to any one of claims 1-7, characterized in that, The break-in activation conditions also include: the engine downtime is greater than the downtime threshold.

9. The pressure valve control method as described in claim 8, characterized in that, The temperature threshold is 0-4℃; the downtime threshold is 30-40 min.

10. The pressure valve control method according to any one of claims 1-7, characterized in that, The predetermined number of times is 3-10 times, and the threshold number of responses is 2-7 times.

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